The present invention relates to encoding and decoding of video data, and more particularly, relates to video encoding and decoding with adaptive restoration for fidelity enhancement.
Popular video coding standards, such as ITU-T standards denoted as H.26x and ISO/IEC standards denoted as MPEG-x, are developed to compress video data for transmission over a channel with limited frequency bandwidth or storage in a memory with limited capacity. These video coding methods include various coding stages such as intra prediction, transform from spatial domain to frequency domain, quantization, entropy coding, motion estimation and motion compensation, in order to code successive frames. These coding techniques can often result in quantization errors, for example, the quantization errors at block boundaries become visible as ‘edging’ on blocks of video frames.
In order to compensate for these blocking effects, conventional coders employ various methods such as deblocking filters to smooth pixels at the boundaries of each block. Deblocking filters can only work on pixels at the boundaries of blocks, however, and cannot compensate for errors within the blocks. Recent developments, therefore, have seen the utilization of Wiener filters, which work to improve picture quality by minimizing the mean square error between an original signal and a noisy signal (i.e. a signal having quantization errors).
In some cases, Wiener filtering is not the most appropriate method for reducing quantization errors. If Wiener filtering is the only option for reducing quantization errors, the received pictures will not always be of a guaranteed quality.